Method of separating metallic ores



Fatented Sept. 10, 1929.

UNITED STATES PATENT OFFICE.

ROBERT W. LOYD AND BERTCH W. MOYE, F METALINE FALLS, "WASHINGTON.-

METHOD OF SEPABATING METALLIC ORES.

No Drawing.

Our present invention relates to improvements in the method of separating metallic ores by the flotation process, and our im- I proved method is especially applicable for use in the treatment of metallic ores when it is essential that some of the gangue materials be suppressed or depressed and held down in the pulp solution in the cells of the flotation machines, while other material or materials are being floated to the surface, to insure a maximum recovery of the separated metals or minerals, and attain the highest grades of concentrates.

@ur invention consists in the combination and arrangement of a sequence of steps involving the introduction to the ores of the several reagents necessary for the separation of the minerals, as will hereinafter be more fully set forth and claimed.

In the following specification we have described a method or process of separating the metallic ores according to our invention which by experiments, tests, and actual practice, in the production of marketable materials, has proven highly successful in the treatment of ores of different natures. such as a quartz gangue with a small amount of lime stone; a gangue having limestone partly in the form of calcite with a small amount of of carbonaceous limestone with some calcite.

In connection with the treatment of the above indicated materials or ores we have successfully carried out the steps of our meth- 0d in the separation of lead and zinc, by first removing by flotation the lead concentrate,

the zinc concentrates are floated in the zinc circuit of the cells of the flotation machines, and the zinc concentrates are removed or quartz; and a gangue composed principally Application filed December 12, 1927. Serial No. 239,612.

flowed to the launders or other places in usual manner.

In carrying out our process We make use of the usual or approved type of ball mill for grinding the ores preparatory to their feed to the cells of the flotation machines, which machines are arranged in two separate circuits, one circuit including cells for re moval of the lead concentrate and the other circuit including cells for the flotation and removal of the zinc concentrate. In addition the necessary conveyors, classifiers, filters and concentrate bins are employed as usual.

lvVhen the reagents are added to the ore in the grinding mill, as a ball mill, the proportions may be from 4 to 20 pounds-of sodium chloride and .02 to .08 pounds of zinc sulphate per ton of ore. Different grades and natures of ore, we have found by test and experiment, require slightly different proportions within the range indicated by these figures.

The ore, together with the sodium chloride, common table salt) and zinc sulphate, are ground to the proper fineness and thoroughly mixed together in the mill, after which they are fed to the flotation machines together with the required liquids, as water, for the formation of the pulp solution preparatory to the separation of the ores, or minerals in the ores from the gangue.

The pulp solution first passes through the cells of the lead circuit of the flotation machines, and during the agitation of the pulp solution in these cells, the reagents as pine oil and xanthate, are introduced to the pulp to assist in the flotation of the lead concentrate. The xanthate is preferably added in small quantities to each cell and the total quantity may approximate .20 of a pound to a ton of the ore, while the pine oil is introduced to the pulp solution at approximately .05 of a pound to the ton of ore. The'quantity of xanthate may vary and range from .05 to .20 of a pound per ton of the ores.

During the process of aeration, agitation and separation of the materials of the gangue in the cells of the lead circuit, the particles of lead rise and float on the surface of the pulp solution While the material of the zinc concentrate is held down or suppressed. The air bubbles rise freely to the surface carrying with them the particles of lead and the bubbles float the particles to the launders or other apparatus for further treatment of the lead sulphide.

By actual practice we find that the employ ment of the salt or sodium chloride prevents the formation of the usual scum on the surface of the solution, and provides a froth that is brittle but of sufficient capacity to convey the lead particles or flow them to the launders. The presence of the sodium chloride in the pulp solution, we find, tends to keep the fgangue from floating, and increases the effiiciency and action of the other chemicals used as agents or reagents in the floating of the mineral particles, by neutralizing the soluble salts both organic and inorganic.

After the removal by flotation, of. the lead sulphides in the cells of the flotation machines in the lead circuit, the remaining pulp s0lution is transferred to the cells of the flotation machines of the zinc circuit for the flotation of the zinc concentrates, and the required reagents are now added to the pulp to float the zinc particles.

The following agents or reagents, we have found to be successful in the flotation of the zinc particles, and while we have definitely stated the proportions of materials used, it

will be understood that these proportions may be varied within limits in adapting the reagents to ores of Various natures. In the successful flotation of the zinc sulphides we have introduced to a pulp solution of one ton of the ores, 2 pounds of sodium chloride, .30 of a pound of copper sulphate and .20 pound of Barrett #4 oila coal tar product.

Thus in the steps of our invention involved in the flotation treatment of the ores for the separation of lead and zinc concentrates the Sodium chloride, 2 pounds }Ad(led to the ore in the ball Zinc sulphate, 1 pound il In 1. Pine oil, .05 pound }A(1(1ed to the cells in the lead Xanthate, .20 pound circuit.

Sodium chloride, 2 pounds Copper sulphate, .30 pound ggg gg the cell of the zmc Coal tar oil, .20 pound It will be understood that there are other steps in the process or treatment of the ores, in addition to those heretofore described, but our invention is confined to these steps in the process of flotation of the lead and Zinc concentrates or other materials from the gangue in these two circuits.

Having thus fully described our invention, what we claim as new and desire to secure by Letters Patent is:

1. The step in the flotation process of treating ores including lead and zinc ores which consists in grinding together the ores, sodium chloride, and zinc sulphate in proper proportions, adding thereto the liquid to form a pulp solution, and separating the ores by depression of the gangue materials.

2. The steps in the flotation process of treating lead and zinc ores which consists in grinding the ores with sodium chloride and zinc sulphates and adding thereto a supply of water to form a pulp solution; adding pine oil and xanthate to the cells in the lead circuit; and adding sodium chloride, copper sulphate and pine oil to the cells of the zinc circuit.

In testimony whereof we aflix our signatures.

ROBERT W. LOYD. BERTCH W. MOYE. 

